Plamooraph co



c. R. TOWNSEND.

ENDLESS BAND GRINDING AND POLISHING MACHINE.

APPLICATION FILED MAY 1- I917.

Patented July 1, 1919.

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PLANO RAH C. R. TOWNSEND.

ENDLESS BAND GRINDING AND POLISHING MACHINE.

APPLICATION FILED MAY 1. 19!]- Patented July 1, 1919.

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THE COLUMBIA PLANOGRAPN $0.. WASHINGTON. b. C.

CHARLES RALPH TOWNSEND, OF BIRMINGHAM, ENGLAND.

ENDLESS-BAND GRINDING AND PGLISHING MACHINE.

Specification of Letters Patent.

Patented July 1, 1919;

Application filed May 7, 1917. Serial No. 166,984.

To all whom it may concern:

Be it known that I, CHARLES RALPH TowNsnND, subject of the King of GreatBritain, residing at Caxton House, Great Charles street, Birmingham,England, engineer, have invented certain new and useful Improvements inEndless-Band Grinding and Polishing Machines, of which the following isa specification.

This invention relates to grinding and polishing machines of that typein which an endless band, having its outer surfaces formed or providedwith grinding material, runs over two pulleys, one adjacent to each endof a rigid table, and one stretch of said band travels across suchtable. The chief object of the invention is to provide means toautomatically separate the two pulleys over which the endless belt runsin a straight line, which means is always in action whether the'pulleyshafts are parallel or slightly inclined one to the other withoutbringing the endless band into contact with the table.

The invention is represented by the accompanying drawings applied to amachine having a vertically disposed table.

Figure 1 is a side elevation.

Fig. 2 is an end section.

Fig. 3 is a longitudinal sectional detail of the means for slightlyinclining the axis of the movable pulley, and

Fig. 4 is a front elevation with the work support removed.

The frame of the machine comprises the based and the elevated part a towhich latter at a is detachably and transversely adjustably secured thetable 0 over which the one stretch of the endless band d runs from lowerand upper pulleys f and g. The lower pulley f has stationary bearings ata a within the frame. The endless band (i is indicated by a dotted linein Fig. 1 and Fig. 2 only, same not being in position in Fig. 4.

The upper pulley g has bearings one each side said pulley withinbrackets g 9 carried by tubes h and 11 disposed one each side the table0 to slide in lug extensions h 72, and i i of the machines frame part (1such straight line sliding movements being parallel with each other andwith the surface of the table. Said tubes are jointedly connected at hand i with the brackets g 9 By sliding the tubes h and 71 togetherwithin the lug extensions the pulleys f and 9 may be separated farther,to thereby put the necessary stretch and tension upon the endless band(i.

This stretching and tensioning is automatically arranged for from theoperation of the weight w. Collars and m are oppositely fixed one oneach tube, and are, by pivoted links y' m connected with swinging arms nand 0 of a transverse rocking shaft 8 having bearings within themachines frame, a and to which is connected a long arm .12 carrying theweight w, whose position can be adjusted along said arm and then fixedby suitable means such as a set screw 00 The weight normally operates onthe rocking shaft, and, through the short arms, links, and collars,exerts a parallel and even sliding action upon the two tubes h and i,carrying the bearings of the pulley g from the machines frame, in suchmanner that the machine has a large amount of movement separating thetwo pulleys f and o to accommodate a larger range in the different sizesof endless bands, and to automatically tension any of such bands up toits full life, and without any other device except the two pulleys f andg, and the surface of the table 0, making physical contact with theendless band.

To slightly incline the axis of the movable pulley g the collar m isprovided with a screw-threaded bore m to receive an externallyscrew-theaded sleeve 2? revolubly fitted over the tube i between twoadditional collars n and 12 fast on the tube. This sleeve t is adaptedfor revolution by hand, using the collar m as a screw box to bodilyslide the tube 71 a distance quite independent of any operation of theweight m, which has the effect of inclining the axis of the pulley g,the jointing of the tubes at h 2' to the brackets g 9 being necessarywhen this part of the invention is used. After setting the inclinationof the axis of the pulley g the operation of the weight 00 causes allthe collars j, m, a, and o to move as one piece with the tubes h and z',which always move parallel and together.

It is a constructional feature to arrange the axes of the tubes 7L and iin the same plane as the axes of both pulleys 7 and g.

A swinging catch to is carried by the slidable tube 2', and is adaptedfor engagement with a stud w fixed to the machines frame, for thepurpose of holding the pulleys f and advance said slide to and from theband a and table 0. Upon this middle slide is mounted a top slide 9 toform a rest surface for work or a carrier for work. This top slide canbe moved by any suitable mechanical devices truly in a direction atright angles to the movement of the middle slide 7, namely, across therunning band d. If the saddle 3 is tipped at an angle the work surfaceof the top slide 9 is also tipped to the same angle.

The elevated part a is provided at 10 10 with lateral projections towhich complemental projections 0 0 of the table are rigidly clamped bythe pins 11 11. The

pieces 10 10 are formed with slots 12 within:

which the pins 11 may be adjusted. By these devices the table 0 may belaterally adjusted on the machines frame to enable either of itslongitudinal edges 13 13'tobe set to. the adjacent edge of the endlessband d.

Having now described my invention what I claim and desire to secure byLetters Patent is 1. In an endless band grinding and polishing machine,the combination of two end pulleys over which the band runs, a table arranged between the two pulleys and over which one stretch of the bandtravels, a pair of rods carrying one of said pulleys, one at each end ofsaid pulley and arranged, respectively, adjacent the longitudinal edgesof said table and mounted for movement in a straight line longitudinallyof said table, and a weight automatically operating on said rods tonormally separate the twopulleys for tensioning the band and maintainingsame, substantially as described.

2. In an endless band grinding and polishing machine, the combination oftwo end pulleys over which the band runs, a table arranged between thetwo pulleys and over which one stretch of the band travels, meanscarrying one of said pulleys and arranged to slide in a straight linelongitudinally of the table, a transverse rocking shaft, meansconnecting said rocking shaft to said slidable means to impart movementto the latter when said shaft is rocked, and a weight tending to rocksaid shaft to automatically separate the two pulleys for tensioning theband and maintaining same, substantially as described.

3. In an endless band grinding and polishing machine, the combination oftwo end pulleys over which the band runs, a table arranged between thetwo pulleys and over which one stretch of the band travels, a pair ofrods carrying the movable pulley, one mounted adjacent to eachlongitudinal edge of the table, and arranged to slide in a straight linelongitudinally of the table, and one of which is lengthwise adjustableto incline the aXis of the movable pulley, and a weight automaticallyoperating on said rods to normally separate the two pulleys fortensioning the band and maintaining same, substantially as described.

4. In an endless band grinding and polishing machine, the combination oftwo end pulleys over which the band runs, a table arranged between thetwo pulleys and over which one stretch of the band travels, a pair ofrods carrying the movable pulley, one adjacent each of the longitudinaledges of the table, and mounted to slide in a straight linelongitudinally of the table, one of said rods being provided with a pairof collars, a screw-threaded sleeve revolubly fitted over said rodbetween said collars, and a weight automatically operating on said rods,in the one case through the sleeve, to normally separate the two pulleysfor tensioning the band and maintaining same, substantially asdescribed.

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

CHARLES RALPH TOWNSEND.

Witnesses Gno. FUERY. D. LEAKER.

Copies of this patent may be obtained. for five cents each, byaddressing the Commissioner of Patents,

' Washington, D. G.

